Improvement in hot-air furnaces



W. J. TOWNE. Hot-Air Furnace.

No. 213,791. Patented April l, |879.

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WILLIAM J. TOWNE, on NEWTON, MASSACHUSETTS.

IMPROVEMENT IN HOT-AIR FURNACES.

Specication forming part of Letters Patent No. 213,791, dated April 1, 1879; application filed December 5, 1878.

To all whom 'it may concern.-

Bc it known that I, WiLLrAM J. TOWNE, of Newton, in the county of Middlesex and State of Massachusetts, have invented certain Im- 'provements in Hot-Air and other Furnaces and `Stoves, of which the following is a full, clear,

and exact description, reference being had to the accompanying drawings, making part of this specification, in Which- Figure 1 is avertical section through a hotair furnace constructed in accordance With my invention. Fig. 2 is a perspective view of the saine, with the outer casin g removed, a portion of the dome being broken away to show the interior construction.

My invention has for its object to cause the smoke and products ot'combustion in a furnace or stove to be more thoroughly and perfectly consumed than heretofore 5 and consists in a series of perforated air-pipes, arranged one above the other within and around the dome or combustion-chamber of a furnace orstove, and communicating with the outer air, by which arrangement the air, in fine streams, is caused to imp'inge upon the smoke and gases in a series of strata. rIhe first pipe throws a stratum of air into the ignited gases just above the fire-pot. This furnishes oxygen for further combustion till the products otlcombustion reach the next stratum of outside air, opposite the pipe next above, which accelerates the combustion until the gases reach the next pipe above, and, in turn,-the air from this pipe accelerates the combustion, and so on up through the series of pipes, whereby a general ignition and combustion of all, or nearly all, of the smoke and gases within the combustion chamber is insured, with much better results than have heretofore been attained.

My invention also consists in a novel method bf connecting the perforated airpipes,which are arranged within the dome or combustionchamber, by means of nipples and sockets tittin g each other, which construction avoids the use of bolts and screw-connections, and admits of the pipes being readily connected and disconnected to facilitate their removal for repairs or cleaning.

To enable others skilled in the art to understand and use my invention, I will proceed to describe the manner in which I have carried it out.

In the said drawings, A represents the dome or combustion-chamber of a hot-air furnace; B, the flrepot; C, the ash-pit, and D the hotair chamber.

The dome A is of somcwhatlarger diameter than the {ire-pot, forming an oifset or shoulder, a, directly over which is placed a series of perforated air-pipes, b, arranged, one above the other, within and around the interior of the dome or combustion-chamber A, thc pipes b being thus removed out of the direct range of the lire, and thereby prevented from being rapidly burned out, as would be the case it' they were arranged directly over the fire. The pipes b are all constructed alike, so as to be interchangeable, each pipe being provided on its under side with conical nipples c, and on its upper side with short vertical pipes or sockets d, the nipples and sockets fitting each other and affording a ready and convenient means of connecting the air-pipes together without the use of bolts or screw-connections, it being merelynecessary to drop thenipples of one pipe binto the corresponding sockets of the pipe b below, and apply caps c to the sockets d of the upper pipe b of the Whole series, the nipples of the lower pipe fitting into short pipes f, passing up through the shoulder a., which serve to support the whole series of air-pipes b in their proper positions.

The above-described method of connecting the pipes b is simple and effective, and admits of their being readily connected and disconnected, thereby greatly facilitating their removal for repairs or cleansing, and, as one pipe can be used in place of another, no para ticular skill or care is required in replacing them within the combustion-chamber.

To the lower ends of the pipes f are secured pipes g, which extend down into the hot-air chamber D, from which` a supply of air passes through the pipes g f to the pipes l), issuing from the perforations 8 thereof in ne streams, and impinging upon and commingling with the smoke and products of combustion as they rise from the lire below.

By arranging the pipes b one above the other, as shown, the air issuing from the low;

est pipe of the series first impinges upon the smoke and gases contiguous to the fuel, producing their ignition at this point, and causing the smoke and gases in thevieinity of the next pipe b above to be heated sufiicientlytoinsure their ignition when mixed with the air issuing from this pipe, and so on throughout the series; and by thus causing the streams of air to be discharged at different levels within the combustion chamber all, or nearly all, of the smoke and gases therein are ignited and consumed, resulting in an increase of heat with a given quantity ot fuel.

The coal is liever intended to reach the level of the lower pipe b` and consequently its airapertures are less liable to become filled with dust or ashes, while the force of thejets of air issuing from the perforutions S of the pipes also tends to keep them free and clear.

My invention maybe applied to stoves as well as hot-air furnaces, and also to steamboiler and other furnaces, and a series of any desired number of perforated air-pipes b may be employed; but I have found three to answer well and produce goed results.

The air for the supply of the pipes b may be taken from the hotair chamber l), as shown in the drawings, or from the outside ot' the casing, through a suitable passage or passages; but in a hot-air furnace 1 prefer to take the air from the hot-air chamber, as the upward currents through the pipes g tend to draw or attract the air from remote portions of the chamber into contact with the tire-pot and dome, and create a circulation of the air over and around them, causing: it to be more rapidly heated, and thereby increasing the heating capacities of the furnace. In a stove or furnace where there is no hot-air chamber the perforated pipes b would be supplied with air directly from the outside ot' the casing,r through a suitable pipe or pipes.

The gas from the combustion-chamber of the furnace will not enter thel pipes b and descend into the hot-air chamber through the pipes g, for the reason that the upward currents of air are sufiiciently stron g to overcome any tendency of the gas to pass down.

I am aware that stoves have heretofore been constructed with orliices in and around their tire-boxes to discharge streams of the outer air into the tire-pot to accelerate combustion; hence I do not broadly claim discharging the small streams of outer air into the stove to aid complete combustion.

I am also aware that drums have been located within a stove above the tire-pot, said drums communicating with the outer air, and having perforations in their lower faces to discharge streams of air downwardly toward the tire-box; but,

Having thus described my invention, what I claim as my invention, and desire to secure by Letters Patent, is-

1. A series of perforated pipes, b, communicating with the air, and arranged, one above the other, within and around the dome or colubustionchamber of a furnace or stove, and independent of and above the fire-pot, whereby air is caused to be discharged in tine streams, so as to eommingle with the smoke and gaseous products of combustion at different levels, substantially in the manner and for the purpose described.

2. In combination with a series of perforated air-pipes, b, arranged within and around the dome or combustion-chamber of a hot-air fur nace, one or more supply-pipes, g, extending down into the hot-air chamber, to create an upward draft and cause the air to circulate over and around the outside ot' the tire-pot and dome, substantially as set forth.

3. In a furnace or stove, the interchangeable perforated air-pipes b, arranged, one above the other, within and around the dome or combustion-chamber, and connected together by means of nipples and sockets e d, adapted to tit each other, substantiallyin the manner and for the purpose described.

'itness my hand this 2d day of December, Y

WM. J. TOWN E.

In presence ot'- P. E. TEseHEMACHER, W. J. CAMBRIDGE. 

